making page wider

Hi – is it possible to make the page wider whilst still keeping the sidebar (at least on the homepage – I don’t mind removing the sidebar from the rest of the pages to go full-width if that helps).

My photos etc don’t display well, as I have images of publisher files (converted to jpg’s to display on site) etc that have text on them that is unreadable in a size that is small enough to fit in the width of this theme – in my previous theme (duplex) I had a full-width template and they were much more readable. But I like this template better looks wise. thanks.
if you want to see the sort of thing I mean, here is a link to one of the images that is unreadable:
http://surehopechurch.co.uk/monthly-news-sheets